The present claimed invention relates to a responsive glass membrane and a glass electrode comprising the responsive glass membrane to which taint is hardly attached and easily detached without destroying an ionic concentration measurement function.
There are multiple kinds of crystalline form for titanium dioxide (TiO2, titania) and it has been known that crystalline titanium dioxide of an anatase form produces photocatalytic activity when it responds to visible light. Powerful oxidation-reduction properties and superhydrophilic properties are represented as the photocatalytic activity; disinfection treatment is applied to a wall or a floor of a surgery room in a hospital by coating the wall or the floor with titanium dioxide and irradiating it with the ultraviolet radiation by making use of the oxidizing properties of superoxide ion formed in the degradation of H2O, antifog treatment is applied to a side mirror of an automobile or a mirror on a road by coating the mirror with titanium dioxide so that self cleaning can be conducted when it rains by making use of the superhydrophilic properties, or the superhydrophilic properties is also applied to taint prevention of an exterior wall of a building or a sheet for a tent.
Meanwhile, if taint attaches to a responsive glass membrane of an ion selective electrode or a pH electrode, an asymmetry electric potential is produced and an error is caused on a measured value. Then, it requires washing the responsive glass membrane sufficiently by the use of detergent or the like so as to remove the taint attached to the responsive glass membrane every time measurement is conducted in order to keep an accuracy of the measurement. As a result, it is conceivable that washing can be easily conducted if the photocatalytic activity of titanium dioxide is utilized for the responsive glass membrane.
The patent document 1 describes the glass electrode comprising the responsive glass membrane on which surface a titanium dioxide film in a dotted shape is formed and discloses that organohalide is degraded by the titanium dioxide film.    Patent document 1: Japan Patent Laid-open number 2002-14078
However, if a titanium dioxide film is nonuniformly formed on a surface of a glass film and a portion where the titanium dioxide film is formed and a portion where the glass is barely formed are mixed like the glass electrode described in the patent document 1, electrical unevenness would be produced on the responsive glass membrane because the titanium dioxide particulates are negatively-charged. As a result of this, an asymmetry electric potential is generated on the glass electrode, which disturbs accurate measurement.
The present invention provides a responsive glass membrane and a glass electrode comprising the responsive glass membrane to which taint is hardly attached and can be easily detached without hindering a function of measuring the ionic concentration.